juju/model.py

   1 import asyncio
   2 import collections
   3 import json
   4 import logging
   5 import os
   6 import re
   7 import stat
   8 import tempfile
   9 import weakref
  10 import zipfile
  11 from concurrent.futures import CancelledError
  12 from functools import partial
  13 from pathlib import Path
  14
  15 import yaml
  16 import theblues.charmstore
  17 import theblues.errors
  18
  19 from .client import client
  20 from .client import watcher
  21 from .client import connection
  22 from .constraints import parse as parse_constraints, normalize_key
  23 from .delta import get_entity_delta
  24 from .delta import get_entity_class
  25 from .exceptions import DeadEntityException
  26 from .errors import JujuError, JujuAPIError
  27 from .placement import parse as parse_placement
  28
  29 log = logging.getLogger(__name__)
  30
  31
  32 class _Observer(object):
  33     """Wrapper around an observer callable.
  34
  35     This wrapper allows filter criteria to be associated with the
  36     callable so that it's only called for changes that meet the criteria.
  37
  38     """
  39     def __init__(self, callable_, entity_type, action, entity_id, predicate):
  40         self.callable_ = callable_
  41         self.entity_type = entity_type
  42         self.action = action
  43         self.entity_id = entity_id
  44         self.predicate = predicate
  45         if self.entity_id:
  46             self.entity_id = str(self.entity_id)
  47             if not self.entity_id.startswith('^'):
  48                 self.entity_id = '^' + self.entity_id
  49             if not self.entity_id.endswith('$'):
  50                 self.entity_id += '$'
  51
  52     async def __call__(self, delta, old, new, model):
  53         await self.callable_(delta, old, new, model)
  54
  55     def cares_about(self, delta):
  56         """Return True if this observer "cares about" (i.e. wants to be
  57         called) for a this delta.
  58
  59         """
  60         if (self.entity_id and delta.get_id() and
  61                 not re.match(self.entity_id, str(delta.get_id()))):
  62             return False
  63
  64         if self.entity_type and self.entity_type != delta.entity:
  65             return False
  66
  67         if self.action and self.action != delta.type:
  68             return False
  69
  70         if self.predicate and not self.predicate(delta):
  71             return False
  72
  73         return True
  74
  75
  76 class ModelObserver(object):
  77     async def __call__(self, delta, old, new, model):
  78         handler_name = 'on_{}_{}'.format(delta.entity, delta.type)
  79         method = getattr(self, handler_name, self.on_change)
  80         await method(delta, old, new, model)
  81
  82     async def on_change(self, delta, old, new, model):
  83         """Generic model-change handler.
  84
  85         :param delta: :class:`juju.client.overrides.Delta`
  86         :param old: :class:`juju.model.ModelEntity`
  87         :param new: :class:`juju.model.ModelEntity`
  88         :param model: :class:`juju.model.Model`
  89
  90         """
  91         pass
  92
  93
  94 class ModelState(object):
  95     """Holds the state of the model, including the delta history of all
  96     entities in the model.
  97
  98     """
  99     def __init__(self, model):
 100         self.model = model
 101         self.state = dict()
 102
 103     def _live_entity_map(self, entity_type):
 104         """Return an id:Entity map of all the living entities of
 105         type ``entity_type``.
 106
 107         """
 108         return {
 109             entity_id: self.get_entity(entity_type, entity_id)
 110             for entity_id, history in self.state.get(entity_type, {}).items()
 111             if history[-1] is not None
 112         }
 113
 114     @property
 115     def applications(self):
 116         """Return a map of application-name:Application for all applications
 117         currently in the model.
 118
 119         """
 120         return self._live_entity_map('application')
 121
 122     @property
 123     def machines(self):
 124         """Return a map of machine-id:Machine for all machines currently in
 125         the model.
 126
 127         """
 128         return self._live_entity_map('machine')
 129
 130     @property
 131     def units(self):
 132         """Return a map of unit-id:Unit for all units currently in
 133         the model.
 134
 135         """
 136         return self._live_entity_map('unit')
 137
 138     def entity_history(self, entity_type, entity_id):
 139         """Return the history deque for an entity.
 140
 141         """
 142         return self.state[entity_type][entity_id]
 143
 144     def entity_data(self, entity_type, entity_id, history_index):
 145         """Return the data dict for an entity at a specific index of its
 146         history.
 147
 148         """
 149         return self.entity_history(entity_type, entity_id)[history_index]
 150
 151     def apply_delta(self, delta):
 152         """Apply delta to our state and return a copy of the
 153         affected object as it was before and after the update, e.g.:
 154
 155             old_obj, new_obj = self.apply_delta(delta)
 156
 157         old_obj may be None if the delta is for the creation of a new object,
 158         e.g. a new application or unit is deployed.
 159
 160         new_obj will never be None, but may be dead (new_obj.dead == True)
 161         if the object was deleted as a result of the delta being applied.
 162
 163         """
 164         history = (
 165             self.state
 166             .setdefault(delta.entity, {})
 167             .setdefault(delta.get_id(), collections.deque())
 168         )
 169
 170         history.append(delta.data)
 171         if delta.type == 'remove':
 172             history.append(None)
 173
 174         entity = self.get_entity(delta.entity, delta.get_id())
 175         return entity.previous(), entity
 176
 177     def get_entity(
 178             self, entity_type, entity_id, history_index=-1, connected=True):
 179         """Return an object instance for the given entity_type and id.
 180
 181         By default the object state matches the most recent state from
 182         Juju. To get an instance of the object in an older state, pass
 183         history_index, an index into the history deque for the entity.
 184
 185         """
 186
 187         if history_index < 0 and history_index != -1:
 188             history_index += len(self.entity_history(entity_type, entity_id))
 189             if history_index < 0:
 190                 return None
 191
 192         try:
 193             self.entity_data(entity_type, entity_id, history_index)
 194         except IndexError:
 195             return None
 196
 197         entity_class = get_entity_class(entity_type)
 198         return entity_class(
 199             entity_id, self.model, history_index=history_index,
 200             connected=connected)
 201
 202
 203 class ModelEntity(object):
 204     """An object in the Model tree"""
 205
 206     def __init__(self, entity_id, model, history_index=-1, connected=True):
 207         """Initialize a new entity
 208
 209         :param entity_id str: The unique id of the object in the model
 210         :param model: The model instance in whose object tree this
 211             entity resides
 212         :history_index int: The index of this object's state in the model's
 213             history deque for this entity
 214         :connected bool: Flag indicating whether this object gets live updates
 215             from the model.
 216
 217         """
 218         self.entity_id = entity_id
 219         self.model = model
 220         self._history_index = history_index
 221         self.connected = connected
 222         self.connection = model.connection
 223
 224     def __repr__(self):
 225         return '<{} entity_id="{}">'.format(type(self).__name__,
 226                                             self.entity_id)
 227
 228     def __getattr__(self, name):
 229         """Fetch object attributes from the underlying data dict held in the
 230         model.
 231
 232         """
 233         return self.safe_data[name]
 234
 235     def __bool__(self):
 236         return bool(self.data)
 237
 238     def on_change(self, callable_):
 239         """Add a change observer to this entity.
 240
 241         """
 242         self.model.add_observer(
 243             callable_, self.entity_type, 'change', self.entity_id)
 244
 245     def on_remove(self, callable_):
 246         """Add a remove observer to this entity.
 247
 248         """
 249         self.model.add_observer(
 250             callable_, self.entity_type, 'remove', self.entity_id)
 251
 252     @property
 253     def entity_type(self):
 254         """A string identifying the entity type of this object, e.g.
 255         'application' or 'unit', etc.
 256
 257         """
 258         return self.__class__.__name__.lower()
 259
 260     @property
 261     def current(self):
 262         """Return True if this object represents the current state of the
 263         entity in the underlying model.
 264
 265         This will be True except when the object represents an entity at a
 266         non-latest state in history, e.g. if the object was obtained by calling
 267         .previous() on another object.
 268
 269         """
 270         return self._history_index == -1
 271
 272     @property
 273     def dead(self):
 274         """Returns True if this entity no longer exists in the underlying
 275         model.
 276
 277         """
 278         return (
 279             self.data is None or
 280             self.model.state.entity_data(
 281                 self.entity_type, self.entity_id, -1) is None
 282         )
 283
 284     @property
 285     def alive(self):
 286         """Returns True if this entity still exists in the underlying
 287         model.
 288
 289         """
 290         return not self.dead
 291
 292     @property
 293     def data(self):
 294         """The data dictionary for this entity.
 295
 296         """
 297         return self.model.state.entity_data(
 298             self.entity_type, self.entity_id, self._history_index)
 299
 300     @property
 301     def safe_data(self):
 302         """The data dictionary for this entity.
 303
 304         If this `ModelEntity` points to the dead state, it will
 305         raise `DeadEntityException`.
 306
 307         """
 308         if self.data is None:
 309             raise DeadEntityException(
 310                 "Entity {}:{} is dead - its attributes can no longer be "
 311                 "accessed. Use the .previous() method on this object to get "
 312                 "a copy of the object at its previous state.".format(
 313                     self.entity_type, self.entity_id))
 314         return self.data
 315
 316     def previous(self):
 317         """Return a copy of this object as was at its previous state in
 318         history.
 319
 320         Returns None if this object is new (and therefore has no history).
 321
 322         The returned object is always "disconnected", i.e. does not receive
 323         live updates.
 324
 325         """
 326         return self.model.state.get_entity(
 327             self.entity_type, self.entity_id, self._history_index - 1,
 328             connected=False)
 329
 330     def next(self):
 331         """Return a copy of this object at its next state in
 332         history.
 333
 334         Returns None if this object is already the latest.
 335
 336         The returned object is "disconnected", i.e. does not receive
 337         live updates, unless it is current (latest).
 338
 339         """
 340         if self._history_index == -1:
 341             return None
 342
 343         new_index = self._history_index + 1
 344         connected = (
 345             new_index == len(self.model.state.entity_history(
 346                 self.entity_type, self.entity_id)) - 1
 347         )
 348         return self.model.state.get_entity(
 349             self.entity_type, self.entity_id, self._history_index - 1,
 350             connected=connected)
 351
 352     def latest(self):
 353         """Return a copy of this object at its current state in the model.
 354
 355         Returns self if this object is already the latest.
 356
 357         The returned object is always "connected", i.e. receives
 358         live updates from the model.
 359
 360         """
 361         if self._history_index == -1:
 362             return self
 363
 364         return self.model.state.get_entity(self.entity_type, self.entity_id)
 365
 366
 367 class Model(object):
 368     def __init__(self, loop=None):
 369         """Instantiate a new connected Model.
 370
 371         :param loop: an asyncio event loop
 372
 373         """
 374         self.loop = loop or asyncio.get_event_loop()
 375         self.connection = None
 376         self.observers = weakref.WeakValueDictionary()
 377         self.state = ModelState(self)
 378         self.info = None
 379         self._watcher_task = None
 380         self._watch_shutdown = asyncio.Event(loop=self.loop)
 381         self._watch_received = asyncio.Event(loop=self.loop)
 382         self._charmstore = CharmStore(self.loop)
 383
 384     async def connect(self, *args, **kw):
 385         """Connect to an arbitrary Juju model.
 386
 387         args and kw are passed through to Connection.connect()
 388
 389         """
 390         if 'loop' not in kw:
 391             kw['loop'] = self.loop
 392         self.connection = await connection.Connection.connect(*args, **kw)
 393         await self._after_connect()
 394
 395     async def connect_current(self):
 396         """Connect to the current Juju model.
 397
 398         """
 399         self.connection = await connection.Connection.connect_current(
 400             self.loop)
 401         await self._after_connect()
 402
 403     async def connect_model(self, model_name):
 404         """Connect to a specific Juju model by name.
 405
 406         :param model_name:  Format [controller:][user/]model
 407
 408         """
 409         self.connection = await connection.Connection.connect_model(model_name,
 410                                                                     self.loop)
 411         await self._after_connect()
 412
 413     async def _after_connect(self):
 414         """Run initialization steps after connecting to websocket.
 415
 416         """
 417         self._watch()
 418         await self._watch_received.wait()
 419         await self.get_info()
 420
 421     async def disconnect(self):
 422         """Shut down the watcher task and close websockets.
 423
 424         """
 425         self._stop_watching()
 426         if self.connection and self.connection.is_open:
 427             await self._watch_shutdown.wait()
 428             log.debug('Closing model connection')
 429             await self.connection.close()
 430             self.connection = None
 431
 432     async def add_local_charm_dir(self, charm_dir, series):
 433         """Upload a local charm to the model.
 434
 435         This will automatically generate an archive from
 436         the charm dir.
 437
 438         :param charm_dir: Path to the charm directory
 439         :param series: Charm series
 440
 441         """
 442         fh = tempfile.NamedTemporaryFile()
 443         CharmArchiveGenerator(charm_dir).make_archive(fh.name)
 444         with fh:
 445             func = partial(
 446                 self.add_local_charm, fh, series, os.stat(fh.name).st_size)
 447             charm_url = await self.loop.run_in_executor(None, func)
 448
 449         log.debug('Uploaded local charm: %s -> %s', charm_dir, charm_url)
 450         return charm_url
 451
 452     def add_local_charm(self, charm_file, series, size=None):
 453         """Upload a local charm archive to the model.
 454
 455         Returns the 'local:...' url that should be used to deploy the charm.
 456
 457         :param charm_file: Path to charm zip archive
 458         :param series: Charm series
 459         :param size: Size of the archive, in bytes
 460         :return str: 'local:...' url for deploying the charm
 461         :raises: :class:`JujuError` if the upload fails
 462
 463         Uses an https endpoint at the same host:port as the wss.
 464         Supports large file uploads.
 465
 466         .. warning::
 467
 468            This method will block. Consider using :meth:`add_local_charm_dir`
 469            instead.
 470
 471         """
 472         conn, headers, path_prefix = self.connection.https_connection()
 473         path = "%s/charms?series=%s" % (path_prefix, series)
 474         headers['Content-Type'] = 'application/zip'
 475         if size:
 476             headers['Content-Length'] = size
 477         conn.request("POST", path, charm_file, headers)
 478         response = conn.getresponse()
 479         result = response.read().decode()
 480         if not response.status == 200:
 481             raise JujuError(result)
 482         result = json.loads(result)
 483         return result['charm-url']
 484
 485     def all_units_idle(self):
 486         """Return True if all units are idle.
 487
 488         """
 489         for unit in self.units.values():
 490             unit_status = unit.data['agent-status']['current']
 491             if unit_status != 'idle':
 492                 return False
 493         return True
 494
 495     async def reset(self, force=False):
 496         """Reset the model to a clean state.
 497
 498         :param bool force: Force-terminate machines.
 499
 500         This returns only after the model has reached a clean state. "Clean"
 501         means no applications or machines exist in the model.
 502
 503         """
 504         log.debug('Resetting model')
 505         for app in self.applications.values():
 506             await app.destroy()
 507         for machine in self.machines.values():
 508             await machine.destroy(force=force)
 509         await self.block_until(
 510             lambda: len(self.machines) == 0
 511         )
 512
 513     async def block_until(self, *conditions, timeout=None, wait_period=0.5):
 514         """Return only after all conditions are true.
 515
 516         """
 517         async def _block():
 518             while not all(c() for c in conditions):
 519                 await asyncio.sleep(wait_period, loop=self.loop)
 520         await asyncio.wait_for(_block(), timeout, loop=self.loop)
 521
 522     @property
 523     def applications(self):
 524         """Return a map of application-name:Application for all applications
 525         currently in the model.
 526
 527         """
 528         return self.state.applications
 529
 530     @property
 531     def machines(self):
 532         """Return a map of machine-id:Machine for all machines currently in
 533         the model.
 534
 535         """
 536         return self.state.machines
 537
 538     @property
 539     def units(self):
 540         """Return a map of unit-id:Unit for all units currently in
 541         the model.
 542
 543         """
 544         return self.state.units
 545
 546     async def get_info(self):
 547         """Return a client.ModelInfo object for this Model.
 548
 549         Retrieves latest info for this Model from the api server. The
 550         return value is cached on the Model.info attribute so that the
 551         valued may be accessed again without another api call, if
 552         desired.
 553
 554         This method is called automatically when the Model is connected,
 555         resulting in Model.info being initialized without requiring an
 556         explicit call to this method.
 557
 558         """
 559         facade = client.ClientFacade()
 560         facade.connect(self.connection)
 561
 562         self.info = await facade.ModelInfo()
 563         log.debug('Got ModelInfo: %s', vars(self.info))
 564
 565         return self.info
 566
 567     def add_observer(
 568             self, callable_, entity_type=None, action=None, entity_id=None,
 569             predicate=None):
 570         """Register an "on-model-change" callback
 571
 572         Once the model is connected, ``callable_``
 573         will be called each time the model changes. ``callable_`` should
 574         be Awaitable and accept the following positional arguments:
 575
 576             delta - An instance of :class:`juju.delta.EntityDelta`
 577                 containing the raw delta data recv'd from the Juju
 578                 websocket.
 579
 580             old_obj - If the delta modifies an existing object in the model,
 581                 old_obj will be a copy of that object, as it was before the
 582                 delta was applied. Will be None if the delta creates a new
 583                 entity in the model.
 584
 585             new_obj - A copy of the new or updated object, after the delta
 586                 is applied. Will be None if the delta removes an entity
 587                 from the model.
 588
 589             model - The :class:`Model` itself.
 590
 591         Events for which ``callable_`` is called can be specified by passing
 592         entity_type, action, and/or entitiy_id filter criteria, e.g.::
 593
 594             add_observer(
 595                 myfunc,
 596                 entity_type='application', action='add', entity_id='ubuntu')
 597
 598         For more complex filtering conditions, pass a predicate function. It
 599         will be called with a delta as its only argument. If the predicate
 600         function returns True, the ``callable_`` will be called.
 601
 602         """
 603         observer = _Observer(
 604             callable_, entity_type, action, entity_id, predicate)
 605         self.observers[observer] = callable_
 606
 607     def _watch(self):
 608         """Start an asynchronous watch against this model.
 609
 610         See :meth:`add_observer` to register an onchange callback.
 611
 612         """
 613         async def _start_watch():
 614             self._watch_shutdown.clear()
 615             try:
 616                 allwatcher = watcher.AllWatcher()
 617                 self._watch_conn = await self.connection.clone()
 618                 allwatcher.connect(self._watch_conn)
 619                 while True:
 620                     results = await allwatcher.Next()
 621                     for delta in results.deltas:
 622                         delta = get_entity_delta(delta)
 623                         old_obj, new_obj = self.state.apply_delta(delta)
 624                         # XXX: Might not want to shield at this level
 625                         # We are shielding because when the watcher is
 626                         # canceled (on disconnect()), we don't want all of
 627                         # its children (every observer callback) to be
 628                         # canceled with it. So we shield them. But this means
 629                         # they can *never* be canceled.
 630                         await asyncio.shield(
 631                             self._notify_observers(delta, old_obj, new_obj),
 632                             loop=self.loop)
 633                     self._watch_received.set()
 634             except CancelledError:
 635                 log.debug('Closing watcher connection')
 636                 await self._watch_conn.close()
 637                 self._watch_shutdown.set()
 638                 self._watch_conn = None
 639
 640         log.debug('Starting watcher task')
 641         self._watcher_task = self.loop.create_task(_start_watch())
 642
 643     def _stop_watching(self):
 644         """Stop the asynchronous watch against this model.
 645
 646         """
 647         log.debug('Stopping watcher task')
 648         if self._watcher_task:
 649             self._watcher_task.cancel()
 650
 651     async def _notify_observers(self, delta, old_obj, new_obj):
 652         """Call observing callbacks, notifying them of a change in model state
 653
 654         :param delta: The raw change from the watcher
 655             (:class:`juju.client.overrides.Delta`)
 656         :param old_obj: The object in the model that this delta updates.
 657             May be None.
 658         :param new_obj: The object in the model that is created or updated
 659             by applying this delta.
 660
 661         """
 662         if new_obj and not old_obj:
 663             delta.type = 'add'
 664
 665         log.debug(
 666             'Model changed: %s %s %s',
 667             delta.entity, delta.type, delta.get_id())
 668
 669         for o in self.observers:
 670             if o.cares_about(delta):
 671                 asyncio.ensure_future(o(delta, old_obj, new_obj, self),
 672                                       loop=self.loop)
 673
 674     async def _wait(self, entity_type, entity_id, action, predicate=None):
 675         """
 676         Block the calling routine until a given action has happened to the
 677         given entity
 678
 679         :param entity_type: The entity's type.
 680         :param entity_id: The entity's id.
 681         :param action: the type of action (e.g., 'add', 'change', or 'remove')
 682         :param predicate: optional callable that must take as an
 683             argument a delta, and must return a boolean, indicating
 684             whether the delta contains the specific action we're looking
 685             for. For example, you might check to see whether a 'change'
 686             has a 'completed' status. See the _Observer class for details.
 687
 688         """
 689         q = asyncio.Queue(loop=self.loop)
 690
 691         async def callback(delta, old, new, model):
 692             await q.put(delta.get_id())
 693
 694         self.add_observer(callback, entity_type, action, entity_id, predicate)
 695         entity_id = await q.get()
 696         # object might not be in the entity_map if we were waiting for a
 697         # 'remove' action
 698         return self.state._live_entity_map(entity_type).get(entity_id)
 699
 700     async def _wait_for_new(self, entity_type, entity_id=None, predicate=None):
 701         """Wait for a new object to appear in the Model and return it.
 702
 703         Waits for an object of type ``entity_type`` with id ``entity_id``.
 704         If ``entity_id`` is ``None``, it will wait for the first new entity
 705         of the correct type.
 706
 707         This coroutine blocks until the new object appears in the model.
 708
 709         """
 710         # if the entity is already in the model, just return it
 711         if entity_id in self.state._live_entity_map(entity_type):
 712             return self.state._live_entity_map(entity_type)[entity_id]
 713         # if we know the entity_id, we can trigger on any action that puts
 714         # the enitty into the model; otherwise, we have to watch for the
 715         # next "add" action on that entity_type
 716         action = 'add' if entity_id is None else None
 717         return await self._wait(entity_type, entity_id, action, predicate)
 718
 719     async def wait_for_action(self, action_id):
 720         """Given an action, wait for it to complete."""
 721
 722         if action_id.startswith("action-"):
 723             # if we've been passed action.tag, transform it into the
 724             # id that the api deltas will use.
 725             action_id = action_id[7:]
 726
 727         def predicate(delta):
 728             return delta.data['status'] in ('completed', 'failed')
 729
 730         return await self._wait('action', action_id, 'change', predicate)
 731
 732     async def add_machine(
 733             self, spec=None, constraints=None, disks=None, series=None):
 734         """Start a new, empty machine and optionally a container, or add a
 735         container to a machine.
 736
 737         :param str spec: Machine specification
 738             Examples::
 739
 740                 (None) - starts a new machine
 741                 'lxd' - starts a new machine with one lxd container
 742                 'lxd:4' - starts a new lxd container on machine 4
 743                 'ssh:user@10.10.0.3' - manually provisions a machine with ssh
 744                 'zone=us-east-1a' - starts a machine in zone us-east-1s on AWS
 745                 'maas2.name' - acquire machine maas2.name on MAAS
 746
 747         :param dict constraints: Machine constraints
 748             Example::
 749
 750                 constraints={
 751                     'mem': 256 * MB,
 752                 }
 753
 754         :param list disks: List of disk constraint dictionaries
 755             Example::
 756
 757                 disks=[{
 758                     'pool': 'rootfs',
 759                     'size': 10 * GB,
 760                     'count': 1,
 761                 }]
 762
 763         :param str series: Series, e.g. 'xenial'
 764
 765         Supported container types are: lxd, kvm
 766
 767         When deploying a container to an existing machine, constraints cannot
 768         be used.
 769
 770         """
 771         params = client.AddMachineParams()
 772         params.jobs = ['JobHostUnits']
 773
 774         if spec:
 775             placement = parse_placement(spec)
 776             if placement:
 777                 params.placement = placement[0]
 778
 779         if constraints:
 780             params.constraints = client.Value.from_json(constraints)
 781
 782         if disks:
 783             params.disks = [
 784                 client.Constraints.from_json(o) for o in disks]
 785
 786         if series:
 787             params.series = series
 788
 789         # Submit the request.
 790         client_facade = client.ClientFacade()
 791         client_facade.connect(self.connection)
 792         results = await client_facade.AddMachines([params])
 793         error = results.machines[0].error
 794         if error:
 795             raise ValueError("Error adding machine: %s", error.message)
 796         machine_id = results.machines[0].machine
 797         log.debug('Added new machine %s', machine_id)
 798         return await self._wait_for_new('machine', machine_id)
 799
 800     async def add_relation(self, relation1, relation2):
 801         """Add a relation between two applications.
 802
 803         :param str relation1: '<application>[:<relation_name>]'
 804         :param str relation2: '<application>[:<relation_name>]'
 805
 806         """
 807         app_facade = client.ApplicationFacade()
 808         app_facade.connect(self.connection)
 809
 810         log.debug(
 811             'Adding relation %s <-> %s', relation1, relation2)
 812
 813         try:
 814             result = await app_facade.AddRelation([relation1, relation2])
 815         except JujuAPIError as e:
 816             if 'relation already exists' not in e.message:
 817                 raise
 818             log.debug(
 819                 'Relation %s <-> %s already exists', relation1, relation2)
 820             # TODO: if relation already exists we should return the
 821             # Relation ModelEntity here
 822             return None
 823
 824         def predicate(delta):
 825             endpoints = {}
 826             for endpoint in delta.data['endpoints']:
 827                 endpoints[endpoint['application-name']] = endpoint['relation']
 828             return endpoints == result.endpoints
 829
 830         return await self._wait_for_new('relation', None, predicate)
 831
 832     def add_space(self, name, *cidrs):
 833         """Add a new network space.
 834
 835         Adds a new space with the given name and associates the given
 836         (optional) list of existing subnet CIDRs with it.
 837
 838         :param str name: Name of the space
 839         :param \*cidrs: Optional list of existing subnet CIDRs
 840
 841         """
 842         raise NotImplementedError()
 843
 844     def add_ssh_key(self, key):
 845         """Add a public SSH key to this model.
 846
 847         :param str key: The public ssh key
 848
 849         """
 850         raise NotImplementedError()
 851     add_ssh_keys = add_ssh_key
 852
 853     def add_subnet(self, cidr_or_id, space, *zones):
 854         """Add an existing subnet to this model.
 855
 856         :param str cidr_or_id: CIDR or provider ID of the existing subnet
 857         :param str space: Network space with which to associate
 858         :param str \*zones: Zone(s) in which the subnet resides
 859
 860         """
 861         raise NotImplementedError()
 862
 863     def get_backups(self):
 864         """Retrieve metadata for backups in this model.
 865
 866         """
 867         raise NotImplementedError()
 868
 869     def block(self, *commands):
 870         """Add a new block to this model.
 871
 872         :param str \*commands: The commands to block. Valid values are
 873             'all-changes', 'destroy-model', 'remove-object'
 874
 875         """
 876         raise NotImplementedError()
 877
 878     def get_blocks(self):
 879         """List blocks for this model.
 880
 881         """
 882         raise NotImplementedError()
 883
 884     def get_cached_images(self, arch=None, kind=None, series=None):
 885         """Return a list of cached OS images.
 886
 887         :param str arch: Filter by image architecture
 888         :param str kind: Filter by image kind, e.g. 'lxd'
 889         :param str series: Filter by image series, e.g. 'xenial'
 890
 891         """
 892         raise NotImplementedError()
 893
 894     def create_backup(self, note=None, no_download=False):
 895         """Create a backup of this model.
 896
 897         :param str note: A note to store with the backup
 898         :param bool no_download: Do not download the backup archive
 899         :return str: Path to downloaded archive
 900
 901         """
 902         raise NotImplementedError()
 903
 904     def create_storage_pool(self, name, provider_type, **pool_config):
 905         """Create or define a storage pool.
 906
 907         :param str name: Name to give the storage pool
 908         :param str provider_type: Pool provider type
 909         :param \*\*pool_config: key/value pool configuration pairs
 910
 911         """
 912         raise NotImplementedError()
 913
 914     def debug_log(
 915             self, no_tail=False, exclude_module=None, include_module=None,
 916             include=None, level=None, limit=0, lines=10, replay=False,
 917             exclude=None):
 918         """Get log messages for this model.
 919
 920         :param bool no_tail: Stop after returning existing log messages
 921         :param list exclude_module: Do not show log messages for these logging
 922             modules
 923         :param list include_module: Only show log messages for these logging
 924             modules
 925         :param list include: Only show log messages for these entities
 926         :param str level: Log level to show, valid options are 'TRACE',
 927             'DEBUG', 'INFO', 'WARNING', 'ERROR,
 928         :param int limit: Return this many of the most recent (possibly
 929             filtered) lines are shown
 930         :param int lines: Yield this many of the most recent lines, and keep
 931             yielding
 932         :param bool replay: Yield the entire log, and keep yielding
 933         :param list exclude: Do not show log messages for these entities
 934
 935         """
 936         raise NotImplementedError()
 937
 938     async def deploy(
 939             self, entity_url, application_name=None, bind=None, budget=None,
 940             channel=None, config=None, constraints=None, force=False,
 941             num_units=1, plan=None, resources=None, series=None, storage=None,
 942             to=None):
 943         """Deploy a new service or bundle.
 944
 945         :param str entity_url: Charm or bundle url
 946         :param str application_name: Name to give the service
 947         :param dict bind: <charm endpoint>:<network space> pairs
 948         :param dict budget: <budget name>:<limit> pairs
 949         :param str channel: Charm store channel from which to retrieve
 950             the charm or bundle, e.g. 'development'
 951         :param dict config: Charm configuration dictionary
 952         :param constraints: Service constraints
 953         :type constraints: :class:`juju.Constraints`
 954         :param bool force: Allow charm to be deployed to a machine running
 955             an unsupported series
 956         :param int num_units: Number of units to deploy
 957         :param str plan: Plan under which to deploy charm
 958         :param dict resources: <resource name>:<file path> pairs
 959         :param str series: Series on which to deploy
 960         :param dict storage: Storage constraints TODO how do these look?
 961         :param to: Placement directive as a string. For example:
 962
 963             '23' - place on machine 23
 964             'lxd:7' - place in new lxd container on machine 7
 965             '24/lxd/3' - place in container 3 on machine 24
 966
 967             If None, a new machine is provisioned.
 968
 969
 970         TODO::
 971
 972             - application_name is required; fill this in automatically if not
 973               provided by caller
 974             - series is required; how do we pick a default?
 975
 976         """
 977         if to:
 978             placement = parse_placement(to)
 979         else:
 980             placement = []
 981
 982         if storage:
 983             storage = {
 984                 k: client.Constraints(**v)
 985                 for k, v in storage.items()
 986             }
 987
 988         is_local = (
 989             entity_url.startswith('local:') or
 990             os.path.isdir(entity_url)
 991         )
 992         entity_id = await self.charmstore.entityId(entity_url) \
 993             if not is_local else entity_url
 994
 995         app_facade = client.ApplicationFacade()
 996         client_facade = client.ClientFacade()
 997         app_facade.connect(self.connection)
 998         client_facade.connect(self.connection)
 999
1000         is_bundle = ((is_local and
1001                       (Path(entity_id) / 'bundle.yaml').exists()) or
1002                      (not is_local and 'bundle/' in entity_id))
1003
1004         if is_bundle:
1005             handler = BundleHandler(self)
1006             await handler.fetch_plan(entity_id)
1007             await handler.execute_plan()
1008             extant_apps = {app for app in self.applications}
1009             pending_apps = set(handler.applications) - extant_apps
1010             if pending_apps:
1011                 # new apps will usually be in the model by now, but if some
1012                 # haven't made it yet we'll need to wait on them to be added
1013                 await asyncio.gather(*[
1014                     asyncio.ensure_future(
1015                         self._wait_for_new('application', app_name),
1016                         loop=self.loop)
1017                     for app_name in pending_apps
1018                 ], loop=self.loop)
1019             return [app for name, app in self.applications.items()
1020                     if name in handler.applications]
1021         else:
1022             log.debug(
1023                 'Deploying %s', entity_id)
1024
1025             if not is_local:
1026                 parts = entity_id[3:].split('/')
1027                 if parts[0].startswith('~'):
1028                     parts.pop(0)
1029                 if not application_name:
1030                     application_name = parts[-1].split('-')[0]
1031                 if not series:
1032                     if len(parts) > 1:
1033                         series = parts[0]
1034                     else:
1035                         entity = await self.charmstore.entity(entity_id)
1036                         ss = entity['Meta']['supported-series']
1037                         series = ss['SupportedSeries'][0]
1038                 await client_facade.AddCharm(channel, entity_id)
1039             elif not entity_id.startswith('local:'):
1040                 # We have a local charm dir that needs to be uploaded
1041                 charm_dir = os.path.abspath(
1042                     os.path.expanduser(entity_id))
1043                 series = series or get_charm_series(charm_dir)
1044                 if not series:
1045                     raise JujuError(
1046                         "Couldn't determine series for charm at {}. "
1047                         "Pass a 'series' kwarg to Model.deploy().".format(
1048                             charm_dir))
1049                 entity_id = await self.add_local_charm_dir(charm_dir, series)
1050
1051             app = client.ApplicationDeploy(
1052                 application=application_name,
1053                 channel=channel,
1054                 charm_url=entity_id,
1055                 config=config,
1056                 constraints=parse_constraints(constraints),
1057                 endpoint_bindings=bind,
1058                 num_units=num_units,
1059                 resources=resources,
1060                 series=series,
1061                 storage=storage,
1062             )
1063             app.placement = placement
1064
1065             result = await app_facade.Deploy([app])
1066             errors = [r.error.message for r in result.results if r.error]
1067             if errors:
1068                 raise JujuError('\n'.join(errors))
1069             return await self._wait_for_new('application', application_name)
1070
1071     def destroy(self):
1072         """Terminate all machines and resources for this model.
1073
1074         """
1075         raise NotImplementedError()
1076
1077     async def destroy_unit(self, *unit_names):
1078         """Destroy units by name.
1079
1080         """
1081         app_facade = client.ApplicationFacade()
1082         app_facade.connect(self.connection)
1083
1084         log.debug(
1085             'Destroying unit%s %s',
1086             's' if len(unit_names) == 1 else '',
1087             ' '.join(unit_names))
1088
1089         return await app_facade.DestroyUnits(list(unit_names))
1090     destroy_units = destroy_unit
1091
1092     def get_backup(self, archive_id):
1093         """Download a backup archive file.
1094
1095         :param str archive_id: The id of the archive to download
1096         :return str: Path to the archive file
1097
1098         """
1099         raise NotImplementedError()
1100
1101     def enable_ha(
1102             self, num_controllers=0, constraints=None, series=None, to=None):
1103         """Ensure sufficient controllers exist to provide redundancy.
1104
1105         :param int num_controllers: Number of controllers to make available
1106         :param constraints: Constraints to apply to the controller machines
1107         :type constraints: :class:`juju.Constraints`
1108         :param str series: Series of the controller machines
1109         :param list to: Placement directives for controller machines, e.g.::
1110
1111             '23' - machine 23
1112             'lxc:7' - new lxc container on machine 7
1113             '24/lxc/3' - lxc container 3 or machine 24
1114
1115             If None, a new machine is provisioned.
1116
1117         """
1118         raise NotImplementedError()
1119
1120     def get_config(self):
1121         """Return the configuration settings for this model.
1122
1123         """
1124         raise NotImplementedError()
1125
1126     def get_constraints(self):
1127         """Return the machine constraints for this model.
1128
1129         """
1130         raise NotImplementedError()
1131
1132     def grant(self, username, acl='read'):
1133         """Grant a user access to this model.
1134
1135         :param str username: Username
1136         :param str acl: Access control ('read' or 'write')
1137
1138         """
1139         raise NotImplementedError()
1140
1141     def import_ssh_key(self, identity):
1142         """Add a public SSH key from a trusted indentity source to this model.
1143
1144         :param str identity: User identity in the form <lp|gh>:<username>
1145
1146         """
1147         raise NotImplementedError()
1148     import_ssh_keys = import_ssh_key
1149
1150     def get_machines(self, machine, utc=False):
1151         """Return list of machines in this model.
1152
1153         :param str machine: Machine id, e.g. '0'
1154         :param bool utc: Display time as UTC in RFC3339 format
1155
1156         """
1157         raise NotImplementedError()
1158
1159     def get_shares(self):
1160         """Return list of all users with access to this model.
1161
1162         """
1163         raise NotImplementedError()
1164
1165     def get_spaces(self):
1166         """Return list of all known spaces, including associated subnets.
1167
1168         """
1169         raise NotImplementedError()
1170
1171     def get_ssh_key(self):
1172         """Return known SSH keys for this model.
1173
1174         """
1175         raise NotImplementedError()
1176     get_ssh_keys = get_ssh_key
1177
1178     def get_storage(self, filesystem=False, volume=False):
1179         """Return details of storage instances.
1180
1181         :param bool filesystem: Include filesystem storage
1182         :param bool volume: Include volume storage
1183
1184         """
1185         raise NotImplementedError()
1186
1187     def get_storage_pools(self, names=None, providers=None):
1188         """Return list of storage pools.
1189
1190         :param list names: Only include pools with these names
1191         :param list providers: Only include pools for these providers
1192
1193         """
1194         raise NotImplementedError()
1195
1196     def get_subnets(self, space=None, zone=None):
1197         """Return list of known subnets.
1198
1199         :param str space: Only include subnets in this space
1200         :param str zone: Only include subnets in this zone
1201
1202         """
1203         raise NotImplementedError()
1204
1205     def remove_blocks(self):
1206         """Remove all blocks from this model.
1207
1208         """
1209         raise NotImplementedError()
1210
1211     def remove_backup(self, backup_id):
1212         """Delete a backup.
1213
1214         :param str backup_id: The id of the backup to remove
1215
1216         """
1217         raise NotImplementedError()
1218
1219     def remove_cached_images(self, arch=None, kind=None, series=None):
1220         """Remove cached OS images.
1221
1222         :param str arch: Architecture of the images to remove
1223         :param str kind: Image kind to remove, e.g. 'lxd'
1224         :param str series: Image series to remove, e.g. 'xenial'
1225
1226         """
1227         raise NotImplementedError()
1228
1229     def remove_machine(self, *machine_ids):
1230         """Remove a machine from this model.
1231
1232         :param str \*machine_ids: Ids of the machines to remove
1233
1234         """
1235         raise NotImplementedError()
1236     remove_machines = remove_machine
1237
1238     def remove_ssh_key(self, *keys):
1239         """Remove a public SSH key(s) from this model.
1240
1241         :param str \*keys: Keys to remove
1242
1243         """
1244         raise NotImplementedError()
1245     remove_ssh_keys = remove_ssh_key
1246
1247     def restore_backup(
1248             self, bootstrap=False, constraints=None, archive=None,
1249             backup_id=None, upload_tools=False):
1250         """Restore a backup archive to a new controller.
1251
1252         :param bool bootstrap: Bootstrap a new state machine
1253         :param constraints: Model constraints
1254         :type constraints: :class:`juju.Constraints`
1255         :param str archive: Path to backup archive to restore
1256         :param str backup_id: Id of backup to restore
1257         :param bool upload_tools: Upload tools if bootstrapping a new machine
1258
1259         """
1260         raise NotImplementedError()
1261
1262     def retry_provisioning(self):
1263         """Retry provisioning for failed machines.
1264
1265         """
1266         raise NotImplementedError()
1267
1268     def revoke(self, username, acl='read'):
1269         """Revoke a user's access to this model.
1270
1271         :param str username: Username to revoke
1272         :param str acl: Access control ('read' or 'write')
1273
1274         """
1275         raise NotImplementedError()
1276
1277     def run(self, command, timeout=None):
1278         """Run command on all machines in this model.
1279
1280         :param str command: The command to run
1281         :param int timeout: Time to wait before command is considered failed
1282
1283         """
1284         raise NotImplementedError()
1285
1286     def set_config(self, **config):
1287         """Set configuration keys on this model.
1288
1289         :param \*\*config: Config key/values
1290
1291         """
1292         raise NotImplementedError()
1293
1294     def set_constraints(self, constraints):
1295         """Set machine constraints on this model.
1296
1297         :param :class:`juju.Constraints` constraints: Machine constraints
1298
1299         """
1300         raise NotImplementedError()
1301
1302     def get_action_output(self, action_uuid, wait=-1):
1303         """Get the results of an action by ID.
1304
1305         :param str action_uuid: Id of the action
1306         :param int wait: Time in seconds to wait for action to complete
1307
1308         """
1309         raise NotImplementedError()
1310
1311     def get_action_status(self, uuid_or_prefix=None, name=None):
1312         """Get the status of all actions, filtered by ID, ID prefix, or action name.
1313
1314         :param str uuid_or_prefix: Filter by action uuid or prefix
1315         :param str name: Filter by action name
1316
1317         """
1318         raise NotImplementedError()
1319
1320     def get_budget(self, budget_name):
1321         """Get budget usage info.
1322
1323         :param str budget_name: Name of budget
1324
1325         """
1326         raise NotImplementedError()
1327
1328     async def get_status(self, filters=None, utc=False):
1329         """Return the status of the model.
1330
1331         :param str filters: Optional list of applications, units, or machines
1332             to include, which can use wildcards ('*').
1333         :param bool utc: Display time as UTC in RFC3339 format
1334
1335         """
1336         client_facade = client.ClientFacade()
1337         client_facade.connect(self.connection)
1338         return await client_facade.FullStatus(filters)
1339
1340     def sync_tools(
1341             self, all_=False, destination=None, dry_run=False, public=False,
1342             source=None, stream=None, version=None):
1343         """Copy Juju tools into this model.
1344
1345         :param bool all_: Copy all versions, not just the latest
1346         :param str destination: Path to local destination directory
1347         :param bool dry_run: Don't do the actual copy
1348         :param bool public: Tools are for a public cloud, so generate mirrors
1349             information
1350         :param str source: Path to local source directory
1351         :param str stream: Simplestreams stream for which to sync metadata
1352         :param str version: Copy a specific major.minor version
1353
1354         """
1355         raise NotImplementedError()
1356
1357     def unblock(self, *commands):
1358         """Unblock an operation that would alter this model.
1359
1360         :param str \*commands: The commands to unblock. Valid values are
1361             'all-changes', 'destroy-model', 'remove-object'
1362
1363         """
1364         raise NotImplementedError()
1365
1366     def unset_config(self, *keys):
1367         """Unset configuration on this model.
1368
1369         :param str \*keys: The keys to unset
1370
1371         """
1372         raise NotImplementedError()
1373
1374     def upgrade_gui(self):
1375         """Upgrade the Juju GUI for this model.
1376
1377         """
1378         raise NotImplementedError()
1379
1380     def upgrade_juju(
1381             self, dry_run=False, reset_previous_upgrade=False,
1382             upload_tools=False, version=None):
1383         """Upgrade Juju on all machines in a model.
1384
1385         :param bool dry_run: Don't do the actual upgrade
1386         :param bool reset_previous_upgrade: Clear the previous (incomplete)
1387             upgrade status
1388         :param bool upload_tools: Upload local version of tools
1389         :param str version: Upgrade to a specific version
1390
1391         """
1392         raise NotImplementedError()
1393
1394     def upload_backup(self, archive_path):
1395         """Store a backup archive remotely in Juju.
1396
1397         :param str archive_path: Path to local archive
1398
1399         """
1400         raise NotImplementedError()
1401
1402     @property
1403     def charmstore(self):
1404         return self._charmstore
1405
1406     async def get_metrics(self, *tags):
1407         """Retrieve metrics.
1408
1409         :param str \*tags: Tags of entities from which to retrieve metrics.
1410             No tags retrieves the metrics of all units in the model.
1411         :return: Dictionary of unit_name:metrics
1412
1413         """
1414         log.debug("Retrieving metrics for %s",
1415                   ', '.join(tags) if tags else "all units")
1416
1417         metrics_facade = client.MetricsDebugFacade()
1418         metrics_facade.connect(self.connection)
1419
1420         entities = [client.Entity(tag) for tag in tags]
1421         metrics_result = await metrics_facade.GetMetrics(entities)
1422
1423         metrics = collections.defaultdict(list)
1424
1425         for entity_metrics in metrics_result.results:
1426             error = entity_metrics.error
1427             if error:
1428                 if "is not a valid tag" in error:
1429                     raise ValueError(error.message)
1430                 else:
1431                     raise Exception(error.message)
1432
1433             for metric in entity_metrics.metrics:
1434                 metrics[metric.unit].append(vars(metric))
1435
1436         return metrics
1437
1438
1439 def get_charm_series(path):
1440     """Inspects the charm directory at ``path`` and returns a default
1441     series from its metadata.yaml (the first item in the 'series' list).
1442
1443     Returns None if no series can be determined.
1444
1445     """
1446     md = Path(path) / "metadata.yaml"
1447     if not md.exists():
1448         return None
1449     data = yaml.load(md.open())
1450     series = data.get('series')
1451     return series[0] if series else None
1452
1453
1454 class BundleHandler(object):
1455     """
1456     Handle bundles by using the API to translate bundle YAML into a plan of
1457     steps and then dispatching each of those using the API.
1458     """
1459     def __init__(self, model):
1460         self.model = model
1461         self.charmstore = model.charmstore
1462         self.plan = []
1463         self.references = {}
1464         self._units_by_app = {}
1465         for unit_name, unit in model.units.items():
1466             app_units = self._units_by_app.setdefault(unit.application, [])
1467             app_units.append(unit_name)
1468         self.client_facade = client.ClientFacade()
1469         self.client_facade.connect(model.connection)
1470         self.app_facade = client.ApplicationFacade()
1471         self.app_facade.connect(model.connection)
1472         self.ann_facade = client.AnnotationsFacade()
1473         self.ann_facade.connect(model.connection)
1474
1475     async def _handle_local_charms(self, bundle):
1476         """Search for references to local charms (i.e. filesystem paths)
1477         in the bundle. Upload the local charms to the model, and replace
1478         the filesystem paths with appropriate 'local:' paths in the bundle.
1479
1480         Return the modified bundle.
1481
1482         :param dict bundle: Bundle dictionary
1483         :return: Modified bundle dictionary
1484
1485         """
1486         apps, args = [], []
1487
1488         default_series = bundle.get('series')
1489         for app_name in self.applications:
1490             app_dict = bundle['services'][app_name]
1491             charm_dir = os.path.abspath(os.path.expanduser(app_dict['charm']))
1492             if not os.path.isdir(charm_dir):
1493                 continue
1494             series = (
1495                 app_dict.get('series') or
1496                 default_series or
1497                 get_charm_series(charm_dir)
1498             )
1499             if not series:
1500                 raise JujuError(
1501                     "Couldn't determine series for charm at {}. "
1502                     "Add a 'series' key to the bundle.".format(charm_dir))
1503
1504             # Keep track of what we need to update. We keep a list of apps
1505             # that need to be updated, and a corresponding list of args
1506             # needed to update those apps.
1507             apps.append(app_name)
1508             args.append((charm_dir, series))
1509
1510         if apps:
1511             # If we have apps to update, spawn all the coroutines concurrently
1512             # and wait for them to finish.
1513             charm_urls = await asyncio.gather(*[
1514                 self.model.add_local_charm_dir(*params)
1515                 for params in args
1516             ], loop=self.model.loop)
1517             # Update the 'charm:' entry for each app with the new 'local:' url.
1518             for app_name, charm_url in zip(apps, charm_urls):
1519                 bundle['services'][app_name]['charm'] = charm_url
1520
1521         return bundle
1522
1523     async def fetch_plan(self, entity_id):
1524         is_local = not entity_id.startswith('cs:') and os.path.isdir(entity_id)
1525         if is_local:
1526             bundle_yaml = (Path(entity_id) / "bundle.yaml").read_text()
1527         else:
1528             bundle_yaml = await self.charmstore.files(entity_id,
1529                                                       filename='bundle.yaml',
1530                                                       read_file=True)
1531         self.bundle = yaml.safe_load(bundle_yaml)
1532         self.bundle = await self._handle_local_charms(self.bundle)
1533
1534         self.plan = await self.client_facade.GetBundleChanges(
1535             yaml.dump(self.bundle))
1536
1537         if self.plan.errors:
1538             raise JujuError('\n'.join(self.plan.errors))
1539
1540     async def execute_plan(self):
1541         for step in self.plan.changes:
1542             method = getattr(self, step.method)
1543             result = await method(*step.args)
1544             self.references[step.id_] = result
1545
1546     @property
1547     def applications(self):
1548         return list(self.bundle['services'].keys())
1549
1550     def resolve(self, reference):
1551         if reference and reference.startswith('$'):
1552             reference = self.references[reference[1:]]
1553         return reference
1554
1555     async def addCharm(self, charm, series):
1556         """
1557         :param charm string:
1558             Charm holds the URL of the charm to be added.
1559
1560         :param series string:
1561             Series holds the series of the charm to be added
1562             if the charm default is not sufficient.
1563         """
1564         # We don't add local charms because they've already been added
1565         # by self._handle_local_charms
1566         if charm.startswith('local:'):
1567             return charm
1568
1569         entity_id = await self.charmstore.entityId(charm)
1570         log.debug('Adding %s', entity_id)
1571         await self.client_facade.AddCharm(None, entity_id)
1572         return entity_id
1573
1574     async def addMachines(self, params=None):
1575         """
1576         :param params dict:
1577             Dictionary specifying the machine to add. All keys are optional.
1578             Keys include:
1579
1580             series: string specifying the machine OS series.
1581
1582             constraints: string holding machine constraints, if any. We'll
1583                 parse this into the json friendly dict that the juju api
1584                 expects.
1585
1586             container_type: string holding the type of the container (for
1587                 instance ""lxd" or kvm"). It is not specified for top level
1588                 machines.
1589
1590             parent_id: string holding a placeholder pointing to another
1591                 machine change or to a unit change. This value is only
1592                 specified in the case this machine is a container, in
1593                 which case also ContainerType is set.
1594
1595         """
1596         params = params or {}
1597
1598         # Normalize keys
1599         params = {normalize_key(k): params[k] for k in params.keys()}
1600
1601         # Fix up values, as necessary.
1602         if 'parent_id' in params:
1603             params['parent_id'] = self.resolve(params['parent_id'])
1604
1605         params['constraints'] = parse_constraints(
1606             params.get('constraints'))
1607         params['jobs'] = params.get('jobs', ['JobHostUnits'])
1608
1609         if params.get('container_type') == 'lxc':
1610             log.warning('Juju 2.0 does not support lxc containers. '
1611                         'Converting containers to lxd.')
1612             params['container_type'] = 'lxd'
1613
1614         # Submit the request.
1615         params = client.AddMachineParams(**params)
1616         results = await self.client_facade.AddMachines([params])
1617         error = results.machines[0].error
1618         if error:
1619             raise ValueError("Error adding machine: %s", error.message)
1620         machine = results.machines[0].machine
1621         log.debug('Added new machine %s', machine)
1622         return machine
1623
1624     async def addRelation(self, endpoint1, endpoint2):
1625         """
1626         :param endpoint1 string:
1627         :param endpoint2 string:
1628             Endpoint1 and Endpoint2 hold relation endpoints in the
1629             "application:interface" form, where the application is always a
1630             placeholder pointing to an application change, and the interface is
1631             optional. Examples are "$deploy-42:web" or just "$deploy-42".
1632         """
1633         endpoints = [endpoint1, endpoint2]
1634         # resolve indirect references
1635         for i in range(len(endpoints)):
1636             parts = endpoints[i].split(':')
1637             parts[0] = self.resolve(parts[0])
1638             endpoints[i] = ':'.join(parts)
1639
1640         log.info('Relating %s <-> %s', *endpoints)
1641         return await self.model.add_relation(*endpoints)
1642
1643     async def deploy(self, charm, series, application, options, constraints,
1644                      storage, endpoint_bindings, resources):
1645         """
1646         :param charm string:
1647             Charm holds the URL of the charm to be used to deploy this
1648             application.
1649
1650         :param series string:
1651             Series holds the series of the application to be deployed
1652             if the charm default is not sufficient.
1653
1654         :param application string:
1655             Application holds the application name.
1656
1657         :param options map[string]interface{}:
1658             Options holds application options.
1659
1660         :param constraints string:
1661             Constraints holds the optional application constraints.
1662
1663         :param storage map[string]string:
1664             Storage holds the optional storage constraints.
1665
1666         :param endpoint_bindings map[string]string:
1667             EndpointBindings holds the optional endpoint bindings
1668
1669         :param resources map[string]int:
1670             Resources identifies the revision to use for each resource
1671             of the application's charm.
1672         """
1673         # resolve indirect references
1674         charm = self.resolve(charm)
1675         # stringify all config values for API, and convert to YAML
1676         options = {k: str(v) for k, v in options.items()}
1677         options = yaml.dump({application: options}, default_flow_style=False)
1678         # build param object
1679         app = client.ApplicationDeploy(
1680             charm_url=charm,
1681             series=series,
1682             application=application,
1683             # Pass options to config-yaml rather than config, as
1684             # config-yaml invokes a newer codepath that better handles
1685             # empty strings in the options values.
1686             config_yaml=options,
1687             constraints=parse_constraints(constraints),
1688             storage=storage,
1689             endpoint_bindings=endpoint_bindings,
1690             resources=resources,
1691         )
1692         # do the do
1693         log.info('Deploying %s', charm)
1694         await self.app_facade.Deploy([app])
1695         # ensure the app is in the model for future operations
1696         await self.model._wait_for_new('application', application)
1697         return application
1698
1699     async def addUnit(self, application, to):
1700         """
1701         :param application string:
1702             Application holds the application placeholder name for which a unit
1703             is added.
1704
1705         :param to string:
1706             To holds the optional location where to add the unit, as a
1707             placeholder pointing to another unit change or to a machine change.
1708         """
1709         application = self.resolve(application)
1710         placement = self.resolve(to)
1711         if self._units_by_app.get(application):
1712             # enough units for this application already exist;
1713             # claim one, and carry on
1714             # NB: this should probably honor placement, but the juju client
1715             # doesn't, so we're not bothering, either
1716             unit_name = self._units_by_app[application].pop()
1717             log.debug('Reusing unit %s for %s', unit_name, application)
1718             return self.model.units[unit_name]
1719
1720         log.debug('Adding new unit for %s%s', application,
1721                   ' to %s' % placement if placement else '')
1722         return await self.model.applications[application].add_unit(
1723             count=1,
1724             to=placement,
1725         )
1726
1727     async def expose(self, application):
1728         """
1729         :param application string:
1730             Application holds the placeholder name of the application that must
1731             be exposed.
1732         """
1733         application = self.resolve(application)
1734         log.info('Exposing %s', application)
1735         return await self.model.applications[application].expose()
1736
1737     async def setAnnotations(self, id_, entity_type, annotations):
1738         """
1739         :param id_ string:
1740             Id is the placeholder for the application or machine change
1741             corresponding to the entity to be annotated.
1742
1743         :param entity_type EntityType:
1744             EntityType holds the type of the entity, "application" or
1745             "machine".
1746
1747         :param annotations map[string]string:
1748             Annotations holds the annotations as key/value pairs.
1749         """
1750         entity_id = self.resolve(id_)
1751         try:
1752             entity = self.model.state.get_entity(entity_type, entity_id)
1753         except KeyError:
1754             entity = await self.model._wait_for_new(entity_type, entity_id)
1755         return await entity.set_annotations(annotations)
1756
1757
1758 class CharmStore(object):
1759     """
1760     Async wrapper around theblues.charmstore.CharmStore
1761     """
1762     def __init__(self, loop):
1763         self.loop = loop
1764         self._cs = theblues.charmstore.CharmStore(timeout=5)
1765
1766     def __getattr__(self, name):
1767         """
1768         Wrap method calls in coroutines that use run_in_executor to make them
1769         async.
1770         """
1771         attr = getattr(self._cs, name)
1772         if not callable(attr):
1773             wrapper = partial(getattr, self._cs, name)
1774             setattr(self, name, wrapper)
1775         else:
1776             async def coro(*args, **kwargs):
1777                 method = partial(attr, *args, **kwargs)
1778                 for attempt in range(1, 4):
1779                     try:
1780                         return await self.loop.run_in_executor(None, method)
1781                     except theblues.errors.ServerError:
1782                         if attempt == 3:
1783                             raise
1784                         await asyncio.sleep(1, loop=self.loop)
1785             setattr(self, name, coro)
1786             wrapper = coro
1787         return wrapper
1788
1789
1790 class CharmArchiveGenerator(object):
1791     def __init__(self, path):
1792         self.path = os.path.abspath(os.path.expanduser(path))
1793
1794     def make_archive(self, path):
1795         """Create archive of directory and write to ``path``.
1796
1797         :param path: Path to archive
1798
1799         Ignored::
1800
1801             * build/\* - This is used for packing the charm itself and any
1802                           similar tasks.
1803             * \*/.\*    - Hidden files are all ignored for now.  This will most
1804                           likely be changed into a specific ignore list
1805                           (.bzr, etc)
1806
1807         """
1808         zf = zipfile.ZipFile(path, 'w', zipfile.ZIP_DEFLATED)
1809         for dirpath, dirnames, filenames in os.walk(self.path):
1810             relative_path = dirpath[len(self.path) + 1:]
1811             if relative_path and not self._ignore(relative_path):
1812                 zf.write(dirpath, relative_path)
1813             for name in filenames:
1814                 archive_name = os.path.join(relative_path, name)
1815                 if not self._ignore(archive_name):
1816                     real_path = os.path.join(dirpath, name)
1817                     self._check_type(real_path)
1818                     if os.path.islink(real_path):
1819                         self._check_link(real_path)
1820                         self._write_symlink(
1821                             zf, os.readlink(real_path), archive_name)
1822                     else:
1823                         zf.write(real_path, archive_name)
1824         zf.close()
1825         return path
1826
1827     def _check_type(self, path):
1828         """Check the path
1829         """
1830         s = os.stat(path)
1831         if stat.S_ISDIR(s.st_mode) or stat.S_ISREG(s.st_mode):
1832             return path
1833         raise ValueError("Invalid Charm at % %s" % (
1834             path, "Invalid file type for a charm"))
1835
1836     def _check_link(self, path):
1837         link_path = os.readlink(path)
1838         if link_path[0] == "/":
1839             raise ValueError(
1840                 "Invalid Charm at %s: %s" % (
1841                     path, "Absolute links are invalid"))
1842         path_dir = os.path.dirname(path)
1843         link_path = os.path.join(path_dir, link_path)
1844         if not link_path.startswith(os.path.abspath(self.path)):
1845             raise ValueError(
1846                 "Invalid charm at %s %s" % (
1847                     path, "Only internal symlinks are allowed"))
1848
1849     def _write_symlink(self, zf, link_target, link_path):
1850         """Package symlinks with appropriate zipfile metadata."""
1851         info = zipfile.ZipInfo()
1852         info.filename = link_path
1853         info.create_system = 3
1854         # Magic code for symlinks / py2/3 compat
1855         # 27166663808 = (stat.S_IFLNK | 0755) << 16
1856         info.external_attr = 2716663808
1857         zf.writestr(info, link_target)
1858
1859     def _ignore(self, path):
1860         if path == "build" or path.startswith("build/"):
1861             return True
1862         if path.startswith('.'):
1863             return True